This invention relates to an ink cartridge for supplying ink to a head of a record apparatus, and an assembling method of an atmospheric open valve in the ink cartridge.
An ink jet record apparatus generally comprises a record head mounted on a carriage and moving in the width direction of record paper, and paper feed means for moving the record paper relatively in a direction orthogonal to the move direction of the record head.
Such an ink jet record apparatus prints on record paper by ejecting ink droplets from a record head based on print data.
A record head capable of ejecting black ink, yellow ink, cyan ink, and magenta ink, for example, is mounted on a carriage and in addition to text print in black ink, full-color print is made possible by changing the ink ejection percentage.
Thus, ink cartridges for supplying black ink, yellow ink, cyan ink, and magenta ink to the record head are placed in the main unit of the apparatus.
In the ordinary ink jet record apparatus, the ink cartridges for supplying black ink, yellow ink, cyan ink, and magenta ink are mounted on a carriage and are moved together with the carriage.
In the recent record apparatus, the carriage has been moved at high speed for the purpose of increasing the record speed.
In such a record apparatus, pressure fluctuation occurs in internal ink as an ink supply tube is extended and bent with acceleration and deceleration of the carriage, making unstable ejecting of ink droplets from the record head.
Thus, such an ink cartridge is proposed, that comprises a lower ink storage chamber (ink tank chamber) opened to the atmosphere side, an upper ink storage chamber (ink end chamber) for head connection, connected via an ink flow passage to the lower ink storage chamber, and a differential pressure regulating valve placed at midpoint in a passage connecting the upper ink storage chamber and a head supply port.
According to the ink cartridge, a negative pressure is generated on the head side by negative pressure generation means and the differential pressure regulating valve is opened accordingly for supplying ink to the record head, so that the adverse effect on ink produced by pressure fluctuation mentioned above is lessened and ink can be supplied to the record head at the optimum water head difference.
Such an ink cartridge comprises an atmospheric open valve constructed by: a valve body capable of opening and closing an atmospheric communication hole to make an ink storage chamber and an atmospheric open chamber communicate with each other; and an elastic member capable of pressing the valve body in a closed direction.
As the ink cartridge is mounted to a record apparatus, the atmospheric open valve is opened, whereby the ink storage chamber is made to communicate with the atmospheric side, and on the other hand, as the ink cartridge is detached, the atmospheric open valves is closed, whereby communication between the ink storage chamber and the atmospheric side is shut off.
However, in the assembling structure of the atmospheric open valve in this kind of ink cartridge, the valve body is urged simply by fixing one end part of the elastic member to the inside of the atmospheric open chamber. Therefore, in designing the ink cartridge, the fixing position of the elastic member, etc., needs to be sufficiently considered for determining the urging force of the elastic member. Consequently, the number of design items increases, and design of the ink cartridge is complicated; this is a problem.
It is therefore an object of the invention to provide an ink cartridge and an assembling structure and method of an atmospheric open valve in the ink cartridge, which make it possible to decrease the number of design items and therefore simplify the ink cartridge design.